[Doc] Add the start of an arch overview page (#10368)

.github/workflows/png-lint.yml

@@ -0,0 +1,37 @@
+name: Lint PNG exports from excalidraw
+on:
+  push:
+    branches:
+      - "main"
+    paths:
+      - '*.excalidraw.png'
+      - '.github/workflows/png-lint.yml'
+  pull_request:
+    branches:
+      - "main"
+    paths:
+      - '*.excalidraw.png'
+      - '.github/workflows/png-lint.yml'
+
+env:
+  LC_ALL: en_US.UTF-8
+
+defaults:
+  run:
+    shell: bash
+
+permissions:
+  contents: read
+
+jobs:
+  actionlint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: "Checkout"
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          fetch-depth: 0
+
+      - name: "Run png-lint.sh to check excalidraw exported images"
+        run: |
+          tools/png-lint.sh